Aspects of language behavior including vocabulary, sentence repetition, spontaneous speech and the behavioral context of speech, as well as performance on generalization tasks for both language and cognition will be measured in a sample of 20-children aged 5-12 years old who have been diagnosed as autistic, and in a sample of 20 children, 5-12 years old who have been diagfosed as schizophrenic. Date will also be collected on three control groups: children matched with the autistic and schizophrenic children for (a) mean length of utterance in spontaneous speech; (b) performance score on the Seguin form board task; and (c) chronological age. The goal of the research is to generate a detailed description of the language behavior of schizophrenic and autistic children through standard test scores and analysis of the spontaneous speech situation--the complexity and developmental level of the speech, appropriateness of the gestures involved, and context awareness revealed. This data in turn will be used to provide evidence toward a resolution of 4 theoretical controversies: (1.) are autism and childhood schizophrenia a single syndrome or separate syndromes?; (2.) are they the result of local brain damage or a general function (reticular activating system) impairment?; (3.) is their behavior delayed-normal or bizarre?; and (4.) do autistic children have a negative, neutral, or positive response to input intensity?